Chart reading mechanism



Aug. 14, 1962 Filed Nov. 15, 1957 L. S. WILLIAMS CHART READING MECHANISM 13 Sheets-Sheet l INVENTOR.

LAWREN E s WILLIAMS Aug. 14, 1962 L. s. WILLIAMS CHART READING MECHANISM l3 SheetsSheet 2 Filed Nov. 15, 1957 wwwiwwww INVENTOR LAWR E NCE' s. WILLIAMS ATTORNEYS Aug. 14, 1962 s. WILLIAMS 3,049,287

CHART READING MECHANISM Filed Nov. 15, 1957 13 Sheets-Sheet 3 INVENTOR.

LAWRF QJCE S. WILLIAMS ATTORNEYS Aug. 14, 1962 L. s. WILLIAMS 3,049,287

CHART READING MECHANISM Filed Nov. 15, 1957 13 Sheets-Sheet 4 H GH EB [I UEQLQE IE O 9 8 7 6 5 4 3 2 I B UHUHHH/UWHHHF 62 12- 63 Q 7 V I I. 7 I 39.1 'I I I 62 INVENTOR. X63 LAWRENCE s. WILLIAMS ATTORNEYS Aug. 14, 1962 L. s. WILLIAMS CHART READING MECHANISM l3 Sheets-Sheet 5 Filed Nov. 15, 1957 INVENTOR. LAWRENCE S. W

BY ILUAMS g, 1 I ATTJ R/V'J S Aug. 14, 1962 s. WILLIAMS 3,049,287

CHART READING MECHANISM Filed Nov. 15, 1957 13 Sheets-Sheet 6 .IZ- .ZIZZ' INVENTOR- LAWR%I(\ICE s. WILLIAMS ATTOR EYS Aug. 14, 1962 L. s. WILLIAMS CHART READING MECHANISM l5 Sheets-Sheet 8 Filed Nov. 15, 1957 IE 9; E2222 mm mL m T 1W m L E% C I %m Aug. 14, 1962 s. WILLIAMS CHART READING MECHANISM l3 Sheets-Sheet 9 Filed Nov. 15, 1957 INVENTOR. LAWRENCE S. W|LL|A ATTORNEYS Aug. 14, 1962 L. s. WILLIAMS CHART READING MECHANISM l3 Sheets-Sheet 10 Filed Nov. 15, 1957 INVENTOR. LAWRENCE S. W\| L|A[\/|S ATTORNEYS Aug. 14, 1962 L. s. WILLIAMS CHART READING MECHANISM l3 SheetsSheet ll Filed Nov. 15, 1957 a T INVENTOR. LAWRE wcE s. WiLLlAMS ATTORNEYS Aug. 14, 1962 s. WILLIAMS CHART READING MECHANISM Filed Nov. 15, 1957 L 13 Sheets-Sheet 12 ig m INVENTOR.

LAWRENCE S. WILLIAMS BY W I ATTORNEYS Aug. 14, 1962 s. WILLIAMS 3,049,287

CHART READING MECHANISM Filed Nov. 15, 1957 13 Sheets-Sheet 13 I n res f INVENTOR.

LAWFgNCE S. WILLIAMS ATTORNEYS 3,049,287 CHART READING MECHANISM Lawrence S. Williams, Toledo, Ohio, assignor, by mesne assignments, to Toledg Scale Corporation, Toledo, Ohio, a corporation of Ohfio Filed Nov. 15, 1957, Ser. No. 696,784 4 Claims. (Cl. 235-1) This invention relates to mechanical chart reading devices for use in connection with condition responsive instruments 'or mechanisms to sense the position of a condition responsive member and convert such information as received therefrom into a form suitable for operating indicating or recording devices.

As industrial processes and inventory control using condition responsive instruments become more and more exact there is a need for a corresponding increase in the accuracy of reading and recording the indications of the instruments. While the reading device constructed according to the invention may be applied to various types of condition responsive mechanism it is, for illustrative purpose only, described in connection with its use in a weighing scale for read-ing the graduations of a chart that moves according to the weight of a load being weighed and setting mechanism for visual display or recording of weight indications in digital form. The accuracy of a digital indication is limited only by the number of places into which the recording may be resolved. In order to get high accuracy it is necessary to graduate the chart with finely spaced graduations and the difficulty of reading, particularly by mechanical means, is thereby materially increased.

The basic reading device with which the invention is concerned is disclosed in copending application Serial No. 616,517 which was filed on October 17, 1956, the present application being a continuation-in-part of such copending application, and includes a plurality of cooperating permutation members which are individually urged in a direction to engage relatively raised and depressed surfaces of a chart and are retracted from engagement with the chart by means of a common pawl that selectively engages one of two notches in each of the permutation members so as to retract such members without disturbing their relative positions. The common pawl in fully retracted position locks the permutation members against relative motion so that notched peripheries of the members may be searched for aligned notches corresponding to the relative positions as determined by a permutation code.

The industrial weighing scale to which the reading device constructed according to the invention is applied, for illustrative purposes only, is provided with conventional so-called unit weights for increasing the load offsetting capacity.

Many weighing scales, such as the one shown and described in US. Patent No. 2,724,585 issued on November 22, 1955, to R. 0. Bradley and C. H. Maurice, Jr., incorporate unit weights for increasing the load counterbalancing capacity of the scale without decreasing the sensitivity of indication given by the ordinary scale indicator. This is accomplished by means of positionable weights which are placed on the weighing scale mechanism, one at a time, and each of which increases the capacity of the scale by some fixed amount, e.g., 500, 1000, 2000 or 5000 pounds. In scales so equipped, the unit weights may counterbalance as much as nine-tenths of the total weighing capacity of the scale, the remaining portion being counterbalanced by automatic load counterbalancing mechanism and indicated by the regular scale indicator.

In weighing scales having an auxiliary, manipulative unit weight system, it has been customary to make the Fire rates Patent TO the same as the capacity of the automatic load counterbalancing means. Manipulation of the unit weight lifting mechanism places one or more unit weights into cooperative relation with the automatic load counterbalancing mechanism when a load to be weighed exceeds the automatic counterbalancing capacity.

Weighing scales of the electronic type also may be provided with auxiliary load mechanism or so-called electronic unit weights, such as those shown and described in abandoned US. application Serial No. 580,324 filed on April 24, 1956, in the name of R. 0. Bradley. An electronic weighing scale may include a load cell, a balancable network that includes an electrical strain gage operatively connected to the load cell and that is adapted to be unbalanced in response to changes in load applied to the load cell, and a circuit that is connected to the network and that includes a feedback potentiometer having a constant resistance and a sliding contact and means for automatically varying the position of the sliding contact relative to the constant resistance to vary the output voltage of the circuit in accordance with the output voltage of the network, the output voltage of the network being in opposition to the output voltage of the circuit. The auxiliary unit weight load mechanism includes means for adding at least one fixed increment of voltage to the output voltage of the circuit to increase the capacity of the scale.

It is desirable that the value of the unit weight or weights, whether of the mechanical or electrical type, be added automatically to the weight figure selected by the reading device from the chart so that the full weight may be indicated by a recording machine, such as a printer, in one operation. For example, if a load weighing 6000 pounds is placed upon a unit weight-equipped weighing scale having a dial capacity of 5000 pounds, 5000 pounds of the load may be counterbalanced by a unit weight and 1000 pounds of the load may be counterbalanced by the ordinary automatic load counterbalancing mechanism and it is desirable that the 5000 pounds unit weight figure and the 1000 pounds automatic load counterbalancing figure be added together automatically so that the full weight of 6000 pounds may be indicated or recorded by indicating or recording devices in one operation.

It is, accordingly, the principal object of this invention to provide, in a mechanical chart reading device for use in connection with condition responsive instruments or mechanisms to sense the position of a condition responsive member and convert such information as received therefrom into a form suitable for operating indicating or recording devices, means for adding to such information additional, yet related, information, whereby integrated information is obtained automatically and may be indicated or recorded by such indicating or recording devices in one operation. Another object of the invention is to provide, in a weighing scale having automatic load counterbalancing mechanism and selectively operated auxiliary load counterbalancing mechanism, reading means for setting indicating or recording devices according to the weight counterbalanced by the automatic load counterbalancing mechanism and according to the weight counterbalanced by the selectively operated auxiliary load counterbalancing mechanism, whereby an integrated weight figure is obtained automatically and may be indicated or recorded by such device in one operation.

A further object of the invention is to provide, in a mechanical chart reading device having means for intecounterbalancing capacity of each unit weight exactly grating information from a plurality of sources, means for zero suppression, whereby the indication or record ing of redundant zeros is avoided.

A still further object is to provide an accurate mechanical chart reading device that is adapted to integrate information from a plurality of sources and that is simple to operate, yet is of rugged and low cost construction.

Other objects and advantages will be apparent from the following description in which reference is had to the accompanying drawings.

A preferred form of the invention is illustrated in the accompanying drawings.

In the drawings:

FIGURE I is an eleveation of a weighing scale dial mechanism showing the location of the reading device and a recording device operated thereby as they are mounted on a weighing scale mechanism;

FIGURE II is a fragmentary schematic diagram to illustrate some of the operating principles of the device;

FIGURE III is a diametric view of the permutation members and the drive mechanism therefor to show their cooperation with each other and with the chart;

FIGURE IV is a horizontal section through the assembly of permutation members to show the cooperation between the permutation members and the drive therefor;

FIGURE V is a plan view of one of the permutation members to show its notch pattern;

FIGURE VI is a fragmentary plan view of the notched portion of another permutation member to Show a second notch pattern;

FIGURE VII is a front elevation at reduced scale of a weighing scale chart suitable for use with the permuta tion reading device;

FIGURE VIII is an enlarged fragment of the graduated portion of the weighing scale chart illustrated in FIG- URE VII;

FIGURE IX is a section at enlarged scale taken substantially along the line IX-IX of FIGURE VIII to illustrate the shape of the individual chart graduations;

FIGURE X is a section at enlarged scale taken along the line X-X of FIGURE VIII to show the shape of locating notches employed to locate the chart prior to taking a reading;

FIGURE XI is a table showing the permutation code used for each of the graduations of the chart;

FIGURE XII is an exploded view of locating mechanism employed to center the chart graduations prior to taking a reading so as to avoid any possibility of selector pins of the permutation members failing to properly engage the chart graduations;

FIGURE XIII is a plan view of the locating device;

FIGURE XIV is a vertical section along the line XIV-XIV of FIGURE XIII;

FIGURE XV is a plan view of a modified locating device;

FIGURE XVI is an elevational view of the locating device which is shown in FIGURE XV;

FIGURE XVII is an enlarged, elevational view of the device which is illustrated in FIGURE III with the addition of a supporting base and frame embodying adjusting and guiding means for the device and part of the means of the present invention for adding additional, yet related, information to the information received by such device from the chart;

FIGURE XVIII is an elevational view as seen from a position along the line XVIIIXVIII of FIGURE IV looking in the direction indicated by the arrows;

FIGURE XIX is an elevational view as seen from a position along the line XIXXIX of FIGURE IV looking in the direction indicated by the arrows;

FIGURE XX is a plan view of the device which is illustrated in FIGURE XIX;

FIGURE XXI is an end elevational view of the device which is illustrated in FIGURE XIX;

FIGURE XXII is an enlarged vertical, sectional view taken substantially along the line XXII-XXII of FIG- URE XX;

FIGURE XXIII is a fragmentary elevational view of one of the spacers which are shown in FIGURE XVII illustrating modified structure having localized bearing areas to reduce friction between spacers and permutation disks;

FIGURE XXIV is a perspective view of a modification of. the drive for the chart reading device which is shown in FIGURE II;

FIGURE XXV is a perspective view of a modification of the drive which is shown in FIGURE XXIV illustrating means for effecting repeat recording;

FIGURE XXVI is a horizontal, sectional View taken along the line XXVI-XXVI of FIGURE XXV;

FIGURE XXVII is partly in elevation and is partly a schematic view showing mechanism for adding unit weight indication automatically into the chart reading device so that the full weight may be indicated or recorded by indicating or recording devices in one operation;

FIGURE XXVIII is an elevational view which is similar to FIGURE XXVII showing the complete chart reading device and the mechanism for adding unit weight indication into such device;

FIGURE XXIX is an end elevational view taken from a position substantially along the line XXIXXXIX of FIGURE XXVIII looking in the direction indicated by the arrows;

FIGURE XXX is a fragmentary perspective view of part of the chart reading device which is illustrated in FIGURE XXVIII showing means for zero suppression to avoid the indication or recording of redundant zeros; and

FIGURE XXXI is a fragmentary, enlarged and exploded view of the device which is illustrated in FIGURE XXX.

These specific figures and the accompanying description are intended merely to illustrate the invention and not to impose limitations on its scope.

For the purpose of illustration, the chart reading device is shown in connection with an ordinary dial type weighing scale. Such a scale comprises a dial housing 1 that contains automatic load counterbalancing and indicating mechanism which includes a chart 2 that is rotated through increments of angle that are proportional to increments of weight applied to the scale. The chart housing 1 is mounted on the top of a scale column 3 of which only the top portion is shown in FIGURE I.

The chart reading mechanism is contained within a housing 4 attached to the dial housing 1 and is connected through a conduit 5 to a printer or other utilization indication or recording device 6 which is to be operated according to the scale readings. The chart 2 has on its face a series of graduations 7 that are visible through a magnifying lens 8 to provide visual indications of the load on the scale. The face of the chart 2 is also provided with molded graduations or indicia 9 consisting of relatively raised and depressed surfaces, as shown in greater detail in FIGURES VIII and IX constituting the indicia that are sensed by the reading device contained within the housing 4.

FIGURE II shows in schematic form one of each of the essential elements of the reading device while FIG- URE III shows a complete assembly of the sensing and selecting portions of the reading device. Referring first to FIGURE II, a reading of the chart 2 is taken by first advancing a series of sensing pins 10, one of which is shown, by spring-urged rotation of permutation disks 11 to positions at which they are arrested by engagement of the sensing pins 10 with the indicia 9 of the chart 2. Prior to the engagement of the sensing pins 10 with the indicia 9, a cam 12 forming part of a drive member 13, through engagement with a roller 14, drives a resiliently mounted finger 15 toward the chart until its tip 16 engages a row of raised teeth 17 and comes to rest either between adjacent teeth or on the crest of a tooth. Continued motion of the cam follower 14 turns a rubber tired wheel 18 in a direction tending to move the chart 2 so that the tip of the finger 16, if it had lodged on a crest of a tooth 17, is permitted to enter the space between two of the teeth and thus locate the chart 2. If the tip 16 were already engaged in a space bet een two of the teeth 17 the wheel slips leaving the chart 2 in position with the corresponding graduation centered in the path of the sensing pins 10. Thus, the pins either enter squarely into the spaces between indicia 9 or onto the crests depending upon the coding of the indicia for that particular graduation.

After the permutation disks 11 are retracted, without disturbing their relative positions as determined by the engagement of the sensing pins 10 with the chart 2, search pawls 21), one for each decade, carried on pawl arms 21 and each cooperating with four of the permutation disks 11 search notches 22 in the peripheries of the permutation disks 11. As each pawl finds aligned notches in its set of four permutation disks 11 it stops the pawl carrier in a position corresponding to the particular graduation of the chart being sensed. The stopped pawl carriers, through their connections through cables 23, position an indicating or recording device according to the sensed graduation.

The movement of the drive member 13 is produced and controlled by a connecting rod 24 and crank 25 driven by a motor 26 equipped with controls to cause it to drive the crank 25 through one revolution for each start signal.

The sequence of steps in thus taking a reading from the chart 2 is to energize the motor such that it turns! the crank 25 and thus oscillates the drive member 13. This oscillation first drives the cam follower 14 and finger toward the chart to locate it with a graduation accurately in line with the sensing pins it}. During the oscillation of the drive member 13 the permutation disks 11, four for each decade, are driven so that their respective pins 10 engage the chart and then are retracted without disturbing their relative positions with respect to each other to a locking position at which they are held while the searching pawls 20, one for each group of four permutation disks or one for each decade, search the peripheries of the permutation disks ill for the aligned notches. Upon finding the aligned notches the pawls stop the respective pawl carriers 21 in proper indicating positions.

The whole combination or assembly of permutation disks and drive members is shown in greater detail in FIGURE III. The complete stack up of permutation disks 11 for a four place number includes sixteen of the permutation disks 11, four pawl carriers 21, and enough spacers 27 to separate each of the permutation disks 11 from its neighbor or from a pawl carrier 21 as the case may be. Thus, sixteen permutation disks 11 and four pawl carriers 21 plus an extra spacer at the top of the stack requires a total of twenty-one spacers 27. Each of the spacers is provided with bifurcated cars 28 and 29 adapted to slip into notches in support rods of a frame with the rods holding the spacers in alignment and in spaced relation. Each of the spacers also has an inwardly directed notch 30 on the side facing the chart that terminates in a narrow slot 31 adapted to fit into a corresponding groove cut in an axle 32 on which the permutation disks 11 and pawl carriers 21 are journaled. Thus, each of the spacers 27 has a three point support so as to separate the permutation disks and still allow them to move easily as may be required in sensing the chart or in carrying the pawls along the notched peripheries of the permutation disks 11.

The sensing pins it) each have a pointed end 33 that is sharp enough to enter the spaces between alternate graduations and yet blunt enough to avoid cutting the chart material and has its other end curled into a circular loop 34 that is a close sliding fit in a hole cut in the connected permutation disk 11 so that the pin moves in the manner of a fiat ball and socket joint. This particular construction keeps the thickness of the permutation disk and pin a minimum so that it may fit between closely spaced adjacent spacers 27.

The permutation disks 11 are continually urged in a direction tending to drive the sensing pins 10 against the chart by spring teeth 35 of a comb spring 36 that is carried on a common pawl bail 37. The ends of the spring teeth 35 engage notches 38 in the permutation disks. Movement of the permutation disks 1 1 under the influence of the springs 35 is limited by a common pawl 40 that is carried in the bail 37 and arranged to selectively engage either of two notches 41 or 42 of each permutation disk Ill and lock it in position when the pawl engages hooklike portions 43 (FIGURE IV) of the bifurcated ears 29 as the bail '37 is urged counterclockwise, as seen in FIGURES III and IV, by a return spring 44 attached to its lower end. The common pawl 40 is held seated in pivot notches 45 of the bail 37 by a plurality of small springs 46 forming part of the comb spring 36 and attached to the bail 37. The pawl 40 is urged into engagement with the notches 41 or 42 by a light spring 47 also attached to the bail 37. The radial wall of notch 42 is raised at 42a (FIGURE V) as a limit stop guard to avoid complete dis engagement of the pawl 40 should it attempt to jump the notches 41 and 42.

In operation, as the drive member 13 is swept clockwise as seen in FIGURE III or IV it collects the pawl carriers 21 from their previous positions and finally engages an upwardly directed stud 48 carried in an upper arm 49 of the bail 37 so as to drive the bail clockwise through a small distance against the tension of the return spring 44. During the initial movement of the bail 37 it and the permutation disks 11 move as a unit since the disks are held between the spring teeth 35 engaging the notches 38 and the pawl 46 engaging the notches 41 or 42. As the sensing pins 10 engage the chart 2 and drive it against a backup roller 50 the motion of the permutation disks 11 is arrested. The spring teeth 35 yield as the bail 37 continues and the pawl 40 leaves the notches 41 or 42 and slides part way along the smooth periphery of the permutation disks 11 between the notches 41 and 38. This motion is just far enough to make sure that the common pawl 40 is out of the notches. On the return motion of the drive member 13, the spring 44 pulls the common pawl bail 37 counterclockwise so that the common pawl 40 may enter the aligned ones of the notches 41 or 42 in each of the permutation disks according to whether the disk had been advanced by its pin finding a low spot in the chart or whether it had been arrested in the first position with the pin on the crest of a graduation. The continued motion with the common pawl 40 engaged in the permutation disks drives the disks in retracting motion until the common pawl 40 seats behind the hook-like portions 43 of the spacer ears 29. At this point the motion of the common pawl bail 37 is arrested and the permutation disks 1]. are all locked in position.

Continuing motion of the drive member 13 allows the pawl carriers 21 to follow as urged by their drive spring 52, one of which is shown in FIGURE IV connected to its cable 23. The pawl carriers 21 move until their pawls 20 find aligned notches in a particular combination of permutation disks with which they cooperate. It is to be noted that the position of the aligned notch may vary according to the relative positions of the group of disks cooperating with each pawl.

The sensing pins 10 adjacent the chart 2 are guided in slots 54 of a guide plate 55 that is attached to a frame support 56 that serves as the spacing support for the bifurcated ears 28 of the spacers 27. The slots 54 are just Wide enough to admit the pins and, thus, accurately guide them closely adjacent the chart 2. As indicated in FIGURE IV, the guide plate 55 is adjustable relative to the frame support rod 56 and is controlled by an adjusting screw 57 that works in opposition to the common pawl bail return spring 44.

The return springs 52 may be the springs in the indicating or recording mechanism, such as a printer, to maintain tension on the cables 23 or if a commutator, not shown in the drawings, be attached to the pawl carriers 21 the springs 52 may be returned to the frame mechanism merely to apply tension to the cable 23 and do no other useful work. If a printer, as indicated in FIGURE I, is enclosed in the housing 6 the cables 23 are run through the conduit from the selector mechanism in the housing 4.

Referring to FIGURE IV, each cable 23 is passed over an arcuate surface or periphery 58 of its pawl carrier 21 and its end is anchored in a hole 59 drilled through the pawl carrier. The spacers 27 hold the cable 23 from slipping off sideways. The radius of the arcuate surface 58 with respect to the axle 32 on which the paw carrier is journaled is selected according to the desired travel of the cable 23 for each increment of indication and the spacing of the notches 22 which determine the angular travel of the pawl carrier.

The permutation disks 11 are made with either of two notch patterns and the selector pawls 20 are arranged with one of its teeth advanced two notch spaces ahead of the other tooth. By thus varying the spacing of the pawl teeth and providing the tWo different patterns for the selector disks it is possible to secure at least eleven different combinations to provide different stopping points for the pawl 20. FIGURES V and VI show the two notch combinations for the permutation disks 11. In the type shown in FIGURE V the notched periphery is divided into twenty-three equal spaces with notches appearing in the first, third, fourth, sixth, ninth, tenth, twelfth, fifteenth, seventeenth, eighteenth, twentieth, and twenty-third spaces counting from left to right. Likewise the permutation pattern shown in FIGURE VI has notches appearing in the first, second, fifth, sixth, ninth, tenth, thirteenth, fourteenth, seventeenth, nineteenth, twentyfirst, and twentythird spaces. These particular notch combinations used in pairs with the offset pawl teeth operate according to the code set forth in FIGURE XI. This code is used in determining the location of the raised and depressed indicia for each of the graduations on the chart 2 to be sensed.

As shown in FIGURE VII, the chart 2 is an annular member carried on a spider 6t) and having rows of graduations 61 on its marginal area. In order to allow for expansion and contraction of the chart 2 and the spider 60 relative to each other due to temperature changes, the spider 66 is slotted radially at 6th: to loosely receive a rivet 610, has openings 60b which loosely receive rivets 61b, and has an aperture 600 which fits snugly about rivet 610. The rivets hold the chart 2 and the spider 60 together, the heads of the rivets being sheared off and the bodies of the rivets shown in section in FIGURE VII for clarity of illustration. The graduations or indicia are preferably molded in the face of the chart in the same manner as phonograph records are made with a plastic or other moldable layer 62 mounted on a metallic backing plate 65 and the graduations being formed in the plastic layer. The arrangement of graduations for a first fragment of the chart is illustrated in FIGURE VIII. This fragment, starting with the zero indicia of the chart, shows only those graduations in the units or lowest order decade and the row of teeth 17 for locating the chart. The teeth 17 along the marginal area of the chart cooperate with the locating finger I5 and have cross sections as shown in FIGURE X wherein each of the teeth is shown substantially as a conventional rack tooth. The tip 16 of the locating finger 15 is formed as a mating tooth so as to seat firmly in the spaces between the teeth 17.

The indicia J with which the sensing pins 10 cooperate are of generally similar shape except for being formed of heavier section inasmuch as the locating pins do not have to fit into the spaces between teeth that are located on adjacent graduations. The chart section shown in FIG- URE VIII, as was mentioned, includes that portion starting at the zero graduation which is shown at the righthand edge. Inasmuch as there are no significant figures to the left of the zero when indicating the zero graduation it is desirable that the indicator show or the recorder record a blank at this position. Therefore, the first graduation carries only the single raised portion in the bottom row or I) row which, according to the chart shown in FIGURE XI, gives a blank for the output indication. The permutation disk combination for this graduation causes the aligned notch to appear at the end of the travel of the pawls 20 or at the last possible position at which an aligned notch may be formed. If an error is made such that the pawl does not find the aligned notch it o'vertravels and the recorder indicates such overtravel by recording some distinctive symbol such as E, in place of a digit. The next graduation, a one, is indicated or denoted by a single raised indicia in the A row; likewise two is indicated by a single indicia in the C row; and the others follow according to the chart. It should be noted that the raised indicia of the chart cause the corresponding permutation disk I1 to be advanced counterclockwise one space as seen in FIGURE III or IV.

Other char combinations may be employed besides the particular code indicated. However, this particular code was selected in order that the number of different parts could be reduced. Thus, with the selected code two each of the permutation disks 11, shown in FIGURES V and VI, may be employed in each decade in combination with the offset pawl 2% If the offset pawl were not employed then each of the four permutation disks cooperating for each decade would have to have its own combination of notches which would make four different parts to be stocked instead of two.

The chart locating mechanism is illustrated in greater detail in FIGURES XII, XIII, and XIV. Referring to FIGURE XII, the cam follower 14 is mounted on the end of a forearm 65 that also carries, as a rigid part thereof, at its elbow end the drive wheel 18 that engages the chart to urge it forward so as to move any tooth 17 falling below the finger tip 16 out of the way and allow the tip 16 of the finger 15 to fall into the space between adjacent teeth 17. The arm 65 is pivotally connected through an elbow joint at the axis of the wheel 13 to a second arm 66 which in turn is pivoted on and, by a spring not shown, is continually urged clockwise about a pin 67 fixed in the framework of the scale. A spring 68 at the joint or elbow at the wheel 18 urges the forearm 65 clockwise with respect to the second arm 66 so that the wheel bears against the chart 2 before the elbow joint starts to turn. The spring urged movement of the forearm 65 relative to the second arm 66 is limited by a down turned car 69 on the tail end of the forearm 65 that engages the front surface of the lower arm 66. Normally, the spring 68 rotates the forearm 65 to maintain the ear in engagement with the lower arm. However, when the mechanism is pushed toward the chart by the cam pushing on the cam roller 14 the lateral motion of the wheel 18 is arrested and the cam force against the cam follower 14 then rotates the arm 65 around its connection. with the lower arm 66 thus producing the relative rotation of the wheel 18.

The finger 15 with its tip 16 is carried on the pin 67 and is urged toward the chart by a spring 70 acting between the lower arm 66 and the finger 15. The forward movement of the tfinger 15 is limited by a stop 71 erected from the rear portion of the lower arm 66 in position to engage the chart side of the finger 15.

FIGURE XIV is a section taken through the elbow joint between the arms 65 and 66 and shows a rubber tire 72 mounted on the wheel 18 so as to increase the tractive effort of the wheel on the chart.

In the operation of this mechanism the spring 68 is made stiff enough so that when the wheel 18 engages the chart it pushes the chart back against the backup roller 50 before the spring 68 yields and permits the arm 65 to turn relative to the arm 66. This insures that sufficient force is exerted against the chart to cause it to move even 9 though the tip 16 of the finger should be partially caught on the corner of the crest of a tooth. It is necessary that sufiicient force be exerted at this time so that the tip of the finger 15 will slide across the crest of a tooth 17 and firmly engage in the valley against the side of the next tooth 17 The chart locating mechanism includes a total of three springs, i.e., springs 68, 70 and the one, not shown, which continually urges arm 66 clockwise about pin 67. Such springs each require rather sensitive differential forces for good results. The number of the springs however, can be reduced from three to two by using the device which is illustrated in FIGURES XV and XVI, the modified device having the advantage that accuracy of differential forces need not be considered in mass production of the device.

Referring to FIGURES XV and XVI, the modified chart locating mechanism is alike in principle to the mechanism hereinbefore described and shown in FIG- URES XII-XIV; however, it is shown in reverse orientation so that it can be driven by the motor 26, crank 25, connecting rod 24, and drive member 13 that are located to the left of the chart 2 instead of to the right of the chart 2 as illustrated in FIGURE II, i.e., the locating mechanism shown in FIGURES XII-XIV is driven by a right hand drive and the locating mechanism shown in FIGURES XV and XVI is driven by a left hand drive. Similar reference numerals in FIGURES XII-XIV and in FIGURES XV and XVI refer to parts which are alike in structure and in function.

The cam follower 14a is mounted on the end of a forc arm 65a that also carries, as a rigid part thereof, at its elbow end a rubber tired drive wheel 18a that engages the chart 2 to urge it forward so as to move any chart tooth 17 falling below a finger tip 16a on a finger 15a out of the way permitting the tip 16a to fall into the space between adjacent chart teeth 17. The arm 65a is pivotally connected through an elbow joint at the axis of the wheel 18a to a second arm 66a which in turn is pivoted on and, by a spring 73, is continually urged counterclockwise about a pin 67a fixed in a stationary base 74 carried by the framework of the scale. The spring 73, which extends between a fixed point 75 on an anchor bracket 76 that is attached to the base 74 and a point 77 on the arm 65a, urges the forearm 65a counterclockwise with respect to the second arm 66a so that the wheel 18a bears against the chart 2 before the elbow joint starts to turn. The spring urged movement of the forearm 65a relative to the second arm 66a is limited by a down turned ear 69a on the tail end of the forearm 65a that engages the front surface of the lower arm 66a. Normally, the spring 73 rotates the forearm 65a counterclockwise to maintain the ear 69a in engagement with the lower arm 66a. However, when the centering device is pushed toward the chart by the cam pushing on the cam roller 14a, the lateral motion of the wheel 18a is arrested by the chart 2 and the cam force against the cam follower 14a then rotates the arm 65a around its elbow connection with the lower arm 66a thus producing the relative rotation of the wheel 18a.

The finger 15a with its tip 16a also is carried on the pin 67a and is urged toward the chart by a spring 70:: acting between the lower arm 66a and the finger 15a. The forward movement of the finger 15a is limited by a down turned ear 78 on the finger 15a in position to engage the wheel 18a. Rearward movement of the finger 15a is limited by an end 79 of the spring 70a being pushed against face 80 of the 'lower arm 66a. The pin 67a, as best shown in FIGURE XVI, functions to pivotally support both the finger 15a and the lower arm 66a, the finger 15a and the arm 66a having flat-bottomed, U-shaped ends pivoted on the pin 67a. Similarly, the forearm 65a is pivotally connected through the elbow joint at the axis of the wheel 18a to the second arm 66a at a flat-bottomed, U-shaped end on the forearm, such elbow joint including a bolt 81 and a nut 82 attached to the lower arm 66a with a spacer 83 keeping the arms of the U-shaped end of the forearm apart, the forearm being rockable about the axis of the bolt 81.

The spring 73 is made stiff enough to that when the wheel 18a engages the chart it pushes the chart back against the backup roller 50 before the spring 73 yields appreciably and permits the arm 65a to turn relative to the arm 66a. This insures that sufficient force is exerted against the chart to cause it to move even though the tip 16:: of the finger 15a should be partially caught on the corner of the crest of a chart tooth 17.

In operation, pressure of the cam 12 against the cam follower 14a moves the forearm 65a toward the chart. The forearm 65a carries with it the wheel 18a which is fixed to the forearm, the finger 15a which has its down turned ear 78 spring urged against the Wheel 1811, and the lower arm 66:; which has its front surface in contact with the spring urged, down turned ear 69a on the forearm 65a. The finger tip 16a on the finger 15a contacts the chart first, the finger 15a then pivoting counterclockwise about the axis of the pin 67a in opposition to the spring 79a until the end 79 of the spring 70a contacts the abutment face 80 of the lower arm 66a. Movement of the finger 15a relative to the lower arm 66a is quite limited. Since the fixed point 75 at the end of the spring 73 is close to the pin 67a, the initial movement of the locating device toward the chart may be accomplished with little force, the spring 73 being stretched only slightly during the cycle before the wheel 18a contacts the chart.

Next, the rubber tired wheel 18a contacts the chart and its lateral motion soon is arrested by the chart 2 which is backed up by the backup roller 5th. The cam force then rotates the arm 65a around its elbow connection with the lower arm 66a producing the relative rotation of the wheel 18a, the spring 73 at thi point yielding appreciably. Rotation of the wheel 18a moves the chart 2 so as to move any chart tooth 17 falling below the finger tip 16a on the finger 15a out of the way permitting the spring urged tip 16a to fall into the space between adjacent chart teeth 17. Once the tip 16a falls into the space between adjacent chart teeth 17, the chart can be moved no further about its axis of rotation by the wheel 18a and the wheel 18a merely slips on the surface of the chart until it is withdrawn, it being withdrawn in a very short time, since the chart graduation sensing cycle of the reading device is of short duration. Of course, it may happen that the chart is so located initially by the condition responsive mechanism that the finger tip 16a is moved directly into the space between adjacent chart teeth 17. Under such circumstances, the chart cannot be moved about its axis of rotation by the Wheel 18a and the wheel merely slips on the surface of the chart. However, in any case, the wheel 18a functions to push the resilient chart back against the backup roller 50 in position to be sensed by the sensing pins 10.

The chart locating mechanism operates ahead of the sensing pin It) movement to shift the chart 2 from any half graduation position to the next full graduation so that a sensing pin It) always firmly engages either the crest of a raised portion of a chart graduation or accurately enters a depressed portion. Upon withdrawal of the cam 12, the cam roller 14a follows along under the urging of the spring 73, the spring 73, thus, functioning both as a return spring for the roller 14a and its associated parts and also as a resilient means which gives way to allow the elbow connection to work at the appropriate time. The chart locating mechanism may be summarized in principle as a device employing friction means, i.e., the rubber tired wheel 18a, for tangentially urging the chart, after it has been positioned approximately by condition responsive mechanism, to a centered reading position. The chart locating mechanism shown in FIG- URES XII-XIV and the modified structure shown in FIGURES XV and XVI employ the same such friction means, the friction means eliminating the possibility of error should a sensing pin 10 slide off a raised portion of 1 a graduation because the chart has stopped halfway between two graduations.

The whole combination or assembly of permutation disks, their drive members, and their supporting frame is shown in detail in FIGURE XVII. Sixteen permutation disks 11, four pawl carriers 21, and twenty-one spacers 27 are illustrated in FIGURE XVII. The bifurcated ears 28 (FIGURE III) of the spacers 27 (FIGURE XVII) are adapted to slip into notches 84 in the square support rod 56 of a frame 85 and the bifurcated ears 29 of the spacers 27 are adapted to slip into notches 86' in a round support rod or post 37 of the frame 85, the rods 56 and 87 holding the spacers in aligned and in spaced relationship. As hereinbefore described, each of the spacers 27 also has an inwardly directed notch 30 on the side facing the chart 2 that terminates in a narrow slot 31 adapted to fit into a corresponding groove cut in the axle 32 on which the permutation disks 11, the drive member 13, the bail 37 carrying the comb spring 36, and

the pawl carriers 21 are journaled. Thus, each of the w;

spacers 27 has a three point support so as to separate the permutation disks and still allow themto move easily as may be required in sensing the chart or in carrying the pawls 20 along the notched peripheries of the permutation disks 11.

The frame 85 includes a horizontal lower plate 88 which serves as a support for the rods 56 and 87, there being lower shoulders 39 on the rods which bear upon the lower plate, and which also serves as a support for a post 90 having a lower shoulder 91 that also bears upon the lower plate. A tenon which is not shown but which is on the lower end of the axle 32 is received in a flat member 92 secured to the lower plate 88, there being a shoulder on the tenon which supports the axle from the lower plate and a pair of washers 93 loose on the lower end of the axle between the lower part of the rockable drive member 13 and the flat member 92. The axle 32, rods 56 and 87, and post 90 function as four spacers to support an upper plate 94 that is held in place on upper shoulders 95 of the axle, rods, and post by nuts 96.

Integral with the flat member 92 is a vertical, coneshaped bottomed post or pin 97 which extends through the lower plate 88 well below the plate into a hole 93 in a base @9 that is suitably mounted within the housing 4 (FIGURE I). The base 9? has a vertical slot 100 which communicates with the hole 93 and an integral boss 101 which is split by the slot 1%. A cap screw I02 threaded horizontally through the boss 1M functions to adjust the width of the slot 100 and, therefore, the size of the hole 98. When the screw M2 is loosened, the post 97 carrying the frame 85 can be lifted out of the hole in the base 99. Hence, the reading device including the frame 85 and the stack of permutation disks and their drive members are removable from the base 99 as a unit assembly.

Precise adjustment and proper guiding of the reading device relative to the chart 2 is very important in attaining high accuracy of reading and recording the indications of condition responsive instruments. The frame carrying the reading device is adjustable in a vertical path by loosening the screw 192 so that the pin 97 is free to slide in the hole 98 and by turning a cone-pointed adjustment screw I i-1'93, threaded into the base 99, until the cone point 1M- on the screw 1%, which cooperates with the cone-shaped bottom on the pin 97, moves the pin 97 upwardly in the hole 2% or permits it to move downwardly in the hole depending upon which direction the screw 1&3 is turned. After the frame 85 is located in its proper vertical position, the screw M2 is retightened and a lock nut 1% on the adjustment screw 103 is tightened.

The frame 85 carrying the reading device also is adjustable about the axis of the pin 97 by loosening the screw 1&2 so that the pin 97 is free to slide in the hole 93 and by turning one way or the other an adjustment screw 1 36 that is threaded at 1&7 into the base 99. The screw 1% is of the double shouldered type, one shoulder cooperating with the outer surface of a bracket 108 depending from the lower plate 88 of the frame at an inverted U-shaped slot 169 in the bracket through which slot the screw 1% extends, and the other shoulder cooperating with the inner surface of the bracket 108 at the slot 1% to form a push-pull connection having a line of action so directed that the frame 85 turns when the adjustment screw 106 is turned. After the frame 85 is located in its proper position, the screw 102 is retightened.

Referring to FIGURE XVIII, as hereinbefore descirbed, the sensing pins 10 adjacent the chart 2 are guided in slots 54 of the guide plate 55 that is attached to the frame support 56. The slots 54 are just wide enough to admit the pins and, thus, accurately guide them closely adjacent the chart 2. As indicated in FIGURES IV and XVIII, the guide plate 55 is adjustable relative to the frame support rod 56 by being pivotal about the axis of a horizontal shoulder screw 110 that is threaded into the support 56 and is controlled by the adjusting screw 57 that works in opposition to the common pawl bail return spring 44. The axis of the shoulder screw 110 is near to the upper one of the sensing pins 10.

The backup roller 50 also is adjustable relative to the chart 2; it is mounted for rotation on a bracket 111 that is held in a groove 112 in a plate 113 by means of a pair of adjustment screws 114, the bracket being loosely secured to the ends of the adjustment screws 114, which protrude through holes in the bracket, by clips as indicated in FIGURES XX and XXI. That is, the ends of the adjustment screws 114 and the clips 115 form pushpull connections, the bracket 111 being pulled horizontally into the groove 112 by the clips 115 when the adjustment screws 114 are turned in a direction which removes the screws from the plate 113 and the bracket 111 being pushed out of the groove 112 by shoulders 116 on the adjustment screws 114 when the screws are turned in the other direction. The adjustment screws 114 are threaded through the plate 113 as shown in detail in FIGURE XXII and turn with difficulty because of short, stiff pieces of wire 117 that are urged resiliently by springs 118, attached to the plate 113, against the adjustment screws 114 at right angles to the axes of the screws. This tends to keep the adjustment screws in their adjusted positions. The plate 113 carrying the backup roller 50* and the adjustment screws 114 is mounted as a unit assembly by means of screws 119 to framework 120 of the dial housing 1.

The gap between the back of the chart 2 and the backup roller 50 (see FIGURE IV) can be varied by turning both of the adjustment screws 114 which slides the bracket 111 back or forth horizontally in the groove 112. Also, either one of the adjustment screws can be turned to tilt the backup roller 50 vertically, i.e., to tilt the roller relative to the chart 2.

In adjusting the reading device to locate it properly relative to the chart 2 to attain the highest accuracy in reading the chart, first, the gap between the backup roller 50 and the back of the chart 2 is adjusted, as hereinbefore described, to the width of a gauge. The size of the gap depends on such factors as the stiffness of the chart 2 and the distances that the sensing pins 10 are driven toward the chart. After the gap is once chosen experimentally as the one which gives optimum performance, a gauge is made to quickly determine the size of the gaps in subsequent production of the reading devices.

Second, the backup roller 50 is tilted, as hereinbefore described, to get the common pawl 40 aligned in one of the two notches 41 or 42 of each permutation disk 11. A blank part of the chart 2 is used for this adjustment. To make the adjustment, the drive member 13 is turned clockwise as viewed in FIGURES III and IV until the sensing pins 10 engage such blank part of the 13 chart 2 and drive it against the backup roller 50 and until the common pawl 4-0 leaves the notches 41 or 42 and slides part way along the smooth periphery of the permutation disks 11 between the notches 41 and 38. The backup roller 50 then is tilted until the edge of the common pawl 49 appears to be parallel with the aligned ones of the notches 41 or 42 in each of the permutation disks. The drive member 13 then is allowed to return so that the spring 44 pulls the common pawl bail 37 counterclockwise so that the common pawl 46 may enter the aligned ones of the notches. The common pawl 40 should seat squarely in the bottoms of the aligned ones of the notches as illustrated in FIGURE IV. If it does not, the process is repeated and the backup roller 50 is tilted relative to the chart 2 by trial and error until the 'pawl 40 aligns with the notches properly.

Third, the frame 85 carrying the assembly of permutation disks and drive members is adjusted both vertically and about the axis of the post 97. One of the molded graduations or indicia 9 on the chart 2 is made extra thin and long and serves as an indexing ridge for this adjustment. To make the adjustment, the frame 85 is adjusted vertically, as hereinbefore described, until the upper one of the sensing pins 10 is at about the same elevation as the top of the indexing ridge 9 and then is adjusted about the axis of the post 97, as hereinbefore described, until such upper one of the sensing pins It] is aligned horizontally with the top of the indexing ridge 9', i.e., until such sensing pin 10 is in close juxtaposition with such ridge 9.

Finally, the guide plate 55 is rocked about the axis of the shoulder screw 110, as hereinbefore described and as indicated by the double-ended arrow in FIGURE XVIII. Such axis is near to the upper one of the sensing pins 10 as illustrated in FIGURE XVIII. This angular adjustment is made to align the rest of the sensing pins, the upper one of the pins being previously aligned, with the indexing ridge 9 so that the row of pins is parallel with such ridge.

The adjustments for the chart reading device and for the backup roller 50 provide in a simple structure easily operable means for vertical, horizontal and angular positioning of the sensing pins 10 relative to the condition responsive chart 2 and for locating and positioning the backup roller 50 relative to the chart to obtain optimum performance from the reading device.

The stack of permutation disks 11 and spacers 27 shown in FIGURE XVII comprise flat disks and spacers which contact each other over relatively large bearing areas. Such flat spacers 27 may be modified and formed as shown in FIGURE XXIII wherein a spacer 27a is illustrated having localized bearing areas 121 to reduce friction between spacers and disks.

The reading device may be adapted selectively to be locked indefinitely, after once having sensed the position of the chart 2, to remember the information as received from the chart for repeat recording of such information by means of the structure shown in FIGURES XXV and XXVI. The drive for the chart reading device which is shown in FIGURE II is illustrated in a modified form in FIGURE XXIV. Similar reference numerals in FIG- URE XXIV and in FIGURE II refer to parts which are alike in structure and in function.

Referring to FIGURE XXIV, the movement of the drive member 13 (FIGURE II) is produced and controlled by a connecting rod 24a and crank 25a driven by a cam .122 which is fixed to a cam shaft 123 that is gear-connected to a motor (not shown), the cam shaft 123 being suitably journaled in the base 99 and the motor being hung from the base 99. The physical location of the cam 122 and the motor is at that part of the base which is shown broken away in FIGURE XVII to the right of the stack of disks 11 and spacers 27. The crank 25a is pivoted on a pin 124 carried by the base 99 and is constantly urged toward the cam 122 by means of a return spring which interconnects the base 99 and the crank, a roller 126 on the crank following about the periphery of the cam 122. The motor turns the cam 122 in the direction indicated by the single-ended arrow in FIGURE XXIV through one revolution for each start signal, the motor being equipped with controls to cause it to turn one revolution only for each start signal. Clockwise turning of the cam 122, as viewed in FIGURE XXIV, drives the crank 25a back and forth as indicated by the double-ended arrow to oscillate the drive member 13 as hereinbefore described in connection with the drive shown in FIGURE II.

Ordinarily, the motor 26 (FIGURE 11) which causes oscillation of the drive member 13 also may drive the utilization device 6 (FIGURE I). For example, if the device 6 is a printer, the motor can first cause a complete oscillation of the drive member 13 so that the chart reading device can set the printer according to the weight of a load upon the weighing scale and then the motor can operate printing mechanism to make a print of such weight all in one synchronized operation. Every time that the motor is operated, the reading device senses the chart and sets up the printer and the printer then is operated to make a print. In some instances, however, it is desirable to make repeat prints of a single weight value with the reading device locked indefinitely to remember the information as received from the chart 2. Mechanism for repeat recording or printing is shown in FIG- URES XXV and XXVI. Similar reference numerals in FIGURES XXIV and in FIGURES XXV and XXVI referto parts which are alike in structure and in function.

Referring to FIGURES XXV and XXVI, the drive member 13 (FIGURE II) may be driven by means including a crank 25b which is pivoted on a pin 12% that is carried by a frame (not shown). Also pivoted on the pin 124b is a bracket 127 which carries a roller 12612 that is adapted to be driven by a cam 1221) (FIGURE XXVI). The crank 25b carries at one end thereof a bell crank 128 which is pivoted at 129 to the crank 25b. Adjustably attached to the bell crank 128 is a latch 134) having an abutment surface 131 which locks the bracket 127 in its position shown in FIGURES XXV and XXVI. In such latched position of the bracket 127, the cam 1221) drives the crank 25b through the bracket 127, which cannot move relative to the crank 25b when it is latched, in the same manner as the cam 122 drives the crank 25a (FIG- URE XXIV).

When it is desired to make a repeat recording or a print, a solenoid 132, which is carried by the crank 25b, is energized to pivot the bell crank clockwise as viewed in FIGURE XXVI. This moves the abutment surface 131 of the latch away from its cooperating position with the bracket 1127. This, in turn, breaks the driving connection from the cam 12212 to the crank 25b because the bracket 127 is free to pivot about the axis of the pin 1241) under such circumstances. Rotation of the cam 1221: then merely rocks the bracket 127 about the axis of the pin 12412, a tension spring 133, interconnecting the bracket 127 and the crank 25b, constantly urging the roller 126b, carried by the bracket 127, against the periphery of the cam when the cam falls back. When the solenoid 132 is deenergized, a compression spring 134 returns the latch 130 to the position shown in FIGURES XXV and XXVI.

In operation, to make a single print of the weight of a load upon the scale, the start signal is given to the motor which then turns one revolution and drives the chart reading device, which sets up the printer, and also drives the printer to make a print. To make a repeat print of such weight of the load upon the scale, another such start signal is given to the motor and simultaneously therewith the solenoid 132 is energized to unlatch the bracket 127 allowing the chart reading device to remain stationary while the motor operates the printer to make a second print of the weight value previously set up in the printer. An unlimited number of additional repeat prints can be 

